SS2. Cardio vascular system - Digestion, mobilization, and transport of fats Flashcards
Where is fat absorbed?
In the small intestines
What enzyme degrades triacylglyceride/TAG/fats?
Lipase enzymes
How are triacylglycerides degraded and what is the result?
By breaking the esterlinkages, creates a glycerol backbone with hydroxyl groups, with carboxylic acid group
How are triacylglycerides named when degraded?
fatty acids
What happens when fatty acids are transported into the cells?
1) Return to triacylglycerides
2) Packaged into lipoprotein chyclomicron with fats inside
3) Cells are normally surrounded by lacteal (lymphatic artery) and normal capillary. Cyclomicron enters lacteals bc they’re bigger. Travels to the lymphatic system in ducts, emptying into either left thoracic duct (LTD) or right thoracic duct (RTD) into bloodstream.
What are the enzymes embedded in the capillaries that degrade the chyclomicrons?
Lipoprotein lipase. It is activated upon recognition, breaks triacylglycerides apart. The enzyme is activated by insulin too because they’re often found together.
What is the biggest user of triacylglycerides?
Adipose cells. Take up fatty acids, turn back into triacylglycerides, and into one giant triacylglyceride.
What does the liver do with the cyclomicron remnants?
It takes up the cyclomicron remnants. The glucose inside can be turned to ATP or glycogen or more fatty acids.
What does the liver package triacylglycerides into?
VLDL, very low density lipoprotein.
Where does VLDL turn to?
Capillaries. It’s taken up by degradation caused by the lipoprotein lipase.
How is fat stored in adipose cells used up?
Adipose cells have hormones receptor for e.g. insulin.
If insulin decreases after a meal, glucagon increases. They bind to the hormone receptors, signalling the adipose cells to turn the triacylglycerides to fatty acids by hormone-sensitive lipaserelease into the bloodstream.
How do fatty acids get into the bloodstream when they’re released from adipose cells, and what does it travel with?
They diffuse down their gradient into the blood. Travels with albumin b/c fatty acids are hydrophobic.
What uses the fats that are found in the bloodstream?
Tissues, such as muscles, to generate ATP.
What organ is the biggest consumer of fatty acids?
the liver. It takes the fats and breaks it down to ATP for gluconeogenesis.
